It is a fable:

Original text: There is a man who is good at the fortress, and his horse dies for no reason and enters the wild, and everyone hangs it. His father said: "How can this not be a blessing?" After staying for a few days, his horse came back with a handsome horse, and everyone congratulated him. His father said, "How can this not be a disaster?"? The family was rich in fine horses, and his son was good at riding them. When he fell down and broke his butt, and everyone hung him up, his father said, "How could this not be a blessing?"? After one year of residence, a large number of barbarians entered the fortress, and the strong men led the way to fight. Nineteen of the people who were close to the fortress died. This was because he was lame, so father and son protected each other. ? Translation: Near the fortress, there lived a man who liked to ride horses. Once, his horse ran to the settlement of the Hu people outside Sewai for no apparent reason. After people heard about it, they all felt sorry for him, but his father said to everyone: "Who knew that this was not a good thing?"? A few months later, the lost horse came with a foreign horse. His horse came back, and people congratulated him when they heard about it. But his father said, "Who knows that this is not a bad thing?" The family has a good horse, and his son loves to ride it. One day, his son accidentally fell off his horse and broke his leg. People came to express their condolences, but his father said again: "Who knew this was not a blessing?"? After a year, the Hu people outside the Great Wall moved in large numbers. When attacking the fortress, all the young men in the fortress went to fight, and nine out of ten of them died in the battle. Only this man escaped death because of his lameness, and the father and son were saved. ? Meaning: Good things and bad things in the world are not absolute. Under certain conditions, bad things can lead to good results, and good things can also lead to bad results.

Therefore, it is said that there is misfortune among blessings, and there is blessing among misfortune. The changes are endless, and the truth is very profound!